struct->struct->class in C++ no constructor

["Wesley Smith" <wesley.hoke@xxxxxxxxx>]

Hi,
I've encountered a problem in GCC 4.2.3 that didn't exist in GCC
4.0.x.  Let's say I have:

template<class T>
Tube{
public:
    Tube();
    ~Tube();
};

struct Graph {
   Tube<Ugen> t;
}

struct Clock {
   Graph g;
}

At issue is that Tube<T>'s constructor isn't getting called when Clock
is allocated on the stack.  Is this compliant with the C++ standard?
I thought all classes had their constructors called when instantiated
as an object even as members of structs.  Any ideas?

thanks,
wes